Card readers for reading magnetic data recorded on a card and recording magnetic data onto the card have been used widely. In industries such as financial institutions where card readers are used, so-called skimming in which the magnetic data of a card is illegally acquired using a magnetic head by a criminal attaching the magnetic head to a card insertion part of a card reader has become a large problem. The tricks used for skimming by criminals become more sophisticated year by year, and the situation in which a device for skimming such as a magnetic head for skimming (hereinafter, referred to as an “insert skimmer”) for reading the magnetic data of the card is attached on the inside of a card reader has been occurring. JP-A-2017-174164 discloses a technique for detecting that an insert skimmer has been inserted on the inside of a card reader.
The technique for detecting the insertion of an insert skimmer is not limited to that disclosed in JP-A-2017-174164, and it is advantageous for the prevention of crime to be able to combine and carry out a plurality of techniques.
At least an embodiment of the present invention, in consideration of the aforementioned situation, provides a card reader which can detect that a foreign matter such as an insert skimmer having a specific shape has been inserted on the inside of a card reader by a method which is different from that of JP-A-2017-174164 and a foreign matter detection method.